This invention relates to cartridges and cassettes for containing and storing web-type media material, and more particularly to such a storage container for material which is light and pressure sensitive, and which is normally wound in tension on a container spool.
The invention is particularly adapted for the protection of donor web material containing microencapsulated image-forming chromogenic material, such as made in accordance with the teachings of U.S. Pat. Nos. 4,440,846 and 4,399,209, assigned to the same assignee as this invention. In the above-identified U.S. patents, an imaging system includes a photosensitive layer comprising microcapsules containing a photosensitive composition in the internal phase. This composition is both light and pressure sensitive. It is intended to be imagewise exposed to actinic radiation and thereafter subjected to a uniform rupturing force in which the microcapsules are selectively ruptured and release the internal phase. The microcapsules of the donor sheets are applied to a substrate layer, and form a web of material for use in suitable utilization apparatus. The cartridges of this invention contain such material in spooled form permitting the delivery, handling and insertion of the media material into utilization apparatus.
The web-type donor material is sensitive to locally applied pressure, such as may occur when a web of such material is wound in tension on a spool or core in which there exists a surface discontinuity, in the form of a splice, a joint, or even a piece of tape. Such a discontinuity will result in the damage to a plurality of the immediately adjacent convolutions of the media material.